BRAKE MATH: PSI & Clamping Forces What happens in the real world?
Editor, Brake & Front End Magazine
If the calipers are a single piston floating design with a two-inch diameter pistons (piston surface area = pπR2 x 2), we just multiply pistons surface area by 556 psi and surface area and we get a 3,419 lbs. of clamping force at both front calipers!
In our theoretical example above, we are ignoring some real world factors that influence the amount of clamping force. The reality of it is that not all of the 556 psi makes it to the caliper and some of the force is wasted flexing the caliper and compressing the brake pads.